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Several new liquid-crystalline materials have been synthesized and their properties investigated. These belong to a series of fl-diketones containing different terminal substituents. Mesophases of the smectic C, smectic A and nematie types have been observed in these /~-diketones. Using these ligands many copper(II) and palladium(II) complexes have also been synthesized and their mesogenic behaviour characterized. Microscopic observations and differential scanning calorimetric measurements show that these chelates exhibit the nematic phase. The DSC data also indicate that the nematic phase of the ligands and complexes is associated with very low clearing transition enthalpies. All the metaUonematogens reported are enantiotropic in nature.

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This paper discusses active teaching and learning strategies that have been used in the TeNeT Online tutorials [1]. The focus of these tutorials is to enable rural students to pass the Standard X examination. The highlight of the tutorial is the use of the Question and Answer format. This problem-solving approach is evident in its three-pronged format: Learn, Practice and Test. Every module is based on questions and answers. In the learn mode, students learn the steps to answer a question and thus the concepts behind it. In the practice and evaluation modes, students can test their knowledge and understanding. This approach enhances the element of interactivity in these tutorials. Combined together, the elements of interactivity and problem-solving have made the tutorials a healthy supplement to conventional class rooms.